## directional (`lygia`/`lighting`/`light`/`directional`)

Calculate directional light

Dependencies:

Use:

``````lightDirectional(<vec3> _diffuseColor, <vec3> _specularColor, <vec3> _N, <vec3> _V, <float> _NoV, <float> _f0, out <vec3> _diffuse, out <vec3> _specular)
``````

Check it on Github

``````

#ifndef STR_LIGHT_DIRECTIONAL
#define STR_LIGHT_DIRECTIONAL
struct LightDirectional {
vec3    direction;
vec3    color;
float   intensity;
};
#endif

#ifndef FNC_LIGHT_DIRECTIONAL
#define FNC_LIGHT_DIRECTIONAL
void lightDirectional(
const in vec3 _diffuseColor, const in vec3 _specularColor,
const in vec3 _V,
const in vec3 _Ld, const in vec3 _Lc, const in float _Li,
const in vec3 _N, const in float _NoV, const in float _NoL,
const in float _roughness, const in float _f0,
inout vec3 _diffuse, inout vec3 _specular) {
float dif = diffuse(_Ld, _N, _V, _NoV, _NoL, _roughness);
float spec = specular(_Ld, _N, _V, _NoV, _NoL, _roughness, _f0);

_diffuse  += max(vec3(0.0), _Li * (_diffuseColor * _Lc * dif));
_specular += max(vec3(0.0), _Li * (_specularColor * _Lc * spec));
}

#ifdef STR_MATERIAL
void lightDirectional(
const in vec3 _diffuseColor, const in vec3 _specularColor,
LightDirectional _L, const in Material _mat,
inout vec3 _diffuse, inout vec3 _specular) {

float f0    = max(_mat.f0.r, max(_mat.f0.g, _mat.f0.b));
float NoL   = dot(_mat.normal, _L.direction);

lightDirectional(
_diffuseColor, _specularColor,
_mat.V,
_L.direction, _L.color, _L.intensity,
_mat.normal, _mat.NoV, NoL, _mat.roughness, f0,
_diffuse, _specular);

vec3  h     = normalize(_mat.V + _L.direction);
float NoH   = saturate(dot(_mat.normal, h));
float LoH   = saturate(dot(_L.direction, h));

float scatterVoH = saturate(dot(_mat.V, -_L.direction));
float forwardScatter = exp2(scatterVoH * _mat.subsurfacePower - _mat.subsurfacePower);
float backScatter = saturate(NoL * _mat.subsurfaceThickness + (1.0 - _mat.subsurfaceThickness)) * 0.5;
float subsurface = mix(backScatter, 1.0, forwardScatter) * (1.0 - _mat.subsurfaceThickness);
_diffuse += _mat.subsurfaceColor * (subsurface * diffuseLambert());
#endif
}
#endif

#endif
``````

Dependencies:

Use:

``````lightDirectional(<float3> _diffuseColor, <float3> _specularColor, <float3> _N, <float3> _V, <float> _NoV, <float> _f0, out <float3> _diffuse, out <float3> _specular)
``````

Check it on Github

``````

#ifndef LIGHT_POSITION
#if defined(UNITY_COMPILER_HLSL)
#define LIGHT_POSITION _WorldSpaceLightPos0.xyz
#else
#define LIGHT_POSITION  float3(0.0, 10.0, -50.0)
#endif
#endif

#ifndef LIGHT_COLOR
#if defined(UNITY_COMPILER_HLSL)
#define LIGHT_COLOR     _LightColor0.rgb
#else
#define LIGHT_COLOR     float3(0.5, 0.5, 0.5)
#endif
#endif

#ifndef LIGHT_INTENSITY
#define LIGHT_INTENSITY 1.0
#endif

#ifndef FNC_LIGHT_DIRECTIONAL
#define FNC_LIGHT_DIRECTIONAL

void lightDirectional(float3 _diffuseColor, float3 _specularColor, float3 _N, float3 _V, float _NoV, float _roughness, float _f0, float _shadow, inout float3 _diffuse, inout float3 _specular) {
#ifdef LIGHT_DIRECTION
float3 s = normalize(LIGHT_DIRECTION);
#else
float3 s = normalize(LIGHT_POSITION);
#endif
float NoL = dot(_N, s);
float dif = diffuseOrenNayar(s, _N, _V, _NoV, NoL, _roughness);
float spec = specularCookTorrance(s, _N, _V, _NoV, NoL, _roughness, _f0);
_diffuse += max(0.0, LIGHT_INTENSITY * (_diffuseColor * LIGHT_COLOR * dif) * _shadow);
_specular += max(0.0, LIGHT_INTENSITY * (_specularColor * LIGHT_COLOR * spec) * _shadow);
}

// void lightDirectional(float3 _diffuseColor, float3 _specularColor, float3 _N, float3 _V, float _NoV, float _roughness, float _f0, inout float3 _diffuse, inout float3 _specular) {
//     return lightDirectional(_diffuseColor, _specularColor, _N, _V, _NoV, _roughness, _f0, 1.0, _diffuse, _specular);
// }

#endif
``````